Abstract: Rainfall is one of the most important ways to obtain the water in ecosystems. Among them, the water use strategies of trees can be determined from the response of sap flow velocity to the different rainfall events. The purpose of this study was to investigate the different response of the sap flow from the sample trees to the various rainfall events. The Larix principis-rupprechtii was also taken as the research objects. Three dominance classes were classified, according to their relative heights (Class I, Class II, and Class III). The sap flow velocity of trees and environmental factors were determined before and after different rainfall events from May to October 2022. The data was also collected from the detection of thermal diffusion flow and automatic weather station. Finally, the water use of trees was analyzed using threshold-delay model, Pearson correlation analysis and random forest regression. The results showed that: 1) The sap flow velocity of trees increased significantly after the rainfall event than before. There were the significant differences in the sap flow velocity after the rainfall event among the three types of rainfall events; On the daily scale, the sap flow velocity after the rainfall event was ranked in the descending order of the heavy > light > medium rainfall. The peaks of small and medium rainfall events were dominated by the single peaks. While the double peaks were then dominated in the light and medium rainfall events; The lagged time of the peaks was observed in the initiation of the sap flow event. Both start and peak time of the sap flow were lagged behind the rainfall after the events. The sap flow velocity of trees was significantly negatively correlated with the rainfall amount and duration. The maximum variation in the sap flow velocity before and after the events was ranked in the descending order of the light >medium >heavy rain. 2) The lowest rainfall thresholds that caused the significant responses of sap flow velocity in the Class I (dominant wood), Class II (average wood) and Class III (suppressed wood) were 3.6, 5.4, and 5.6 mm, respectively. The small rainfall events were important for the growth and survival of trees. The response of sap flow velocity to the rainfall shared the lag behavior with the increase of dominance, which were 1.87, 1.54 and 1.24 d, respectively. Different water-use strategies were formed after rainfall events. 3) There was the great variation in the dominant influencing factors of the sap flow velocity after different rainfall events. There was the ever-increasing contribution of the volumetric soil water content to the sap flow velocity after each rainfall events. As such, the content of volumetric soil water was the dominant influencing factor on the sap flow velocity after medium rainfall. While the solar radiation and vapor pressure deficit differences were the environmental factors on the sap flow velocity after light and heavy rainfall; A comparison was then made on the curve-fitting parameters of the sap flow velocity and transpiration variables before and after rainfall. The sap flow velocity in each class of sample trees was the most sensitive to the environmental factors after the medium rainfall. The strongest sensitivity was also observed in the water conductivity after light rainfall. Therefore, the small rainfall events were more likely to promote the water physiological activities of North China larch. A better understanding of hydrological effects was gained to accurately quantify the response of the sap flow of trees to the different rainfall events. The finding can also provide the theoretical support to maintain the health of local forests in the Loess Plateau region.